PRINGLES POTATO CRISPS.RTM. (Pringles) is a trademark of The Procter & Gamble Company of Cincinnati, Ohio. Pringles are commonly shaped individual snack articles having a "saddle" shape, which have been packaged as a single stack of articles in a cylindrical fiberboard laminated can. Several cans may be bundled together in order to sell multiple stacks in a single package. However, multiple cans represent an expensive package. More desirable is a package which has one primary container with a provision for multiple stacks of articles therein.
Pringles and other pre-shaped snack articles are typically fragile and easily broken in rough handling. They are especially susceptible to breakage when stacks contact one another and experience vibration during shipping or when a consumer squeezes a container wall and thereby presses against the curved edges of an article or stack of articles to generate single point contact on opposing sides of the article or stack of articles.
What is needed is an inexpensive single container for multiple stacks of such fragile articles, which withstands the typical hand squeezing forces and separates the stacks such that vibratory contact cannot occur between them. In particular a two stack container is needed.
One reason a cylindrical can has been used for the oval shaped Pringles articles is that each package is first evacuated and then packed under nitrogen. When exposed to shipping over mountains where external atmospheric pressure is two thirds of that at sea level, internal can pressures of 2-4 pounds per square inch may result. A cylindrical can will maintain its shape under these internal vacuum and pressure conditions more easily than any other shape except for a spherical can, which is impractical. However, a cylindrical container for two side-by-side stacks of oval articles would provide considerable empty space within the container and would be excessively large for one-handed handling (over four inches in diameter).
What is needed is a substantially rectangular container for two side-by-side stacks of articles such that container size is minimized and is easily grasped in one hand, but which will maintain its external shape when evacuated or pressurized so that a wrap around label will retain its fit.
Plastic bottles have long been made by blow molding because blow molding provides an inexpensive process and bottle construction. Compartmented packages are found in the art too. However, compartmented blow molded packages are uncommon because of the nature of the blow molding process, which expands a single parison against an internal mold wall. Blow molded containers can be made with multiple layers to incorporate different types of materials possessing barrier properties, e.g. oxygen barrier, also to allow colorants to be used only on the outside of the package and to incorporate regrind back into the package. Containers having corrugations for increasing side wall strength are also found in the art. However, the combination of all of these features has not been found in the art.
What is needed is a blow molded container having two separate compartments to protect fragile products and corrugated side walls to minimize material while providing deflection strength for squeeze strength as well as pressure/vacuum resistance, and which is made of an inexpensive oxygen and moisture barrier structure.